From owner-freebsd-questions@FreeBSD.ORG Sat Sep 12 13:10:26 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C20831065695 for ; Sat, 12 Sep 2009 13:10:26 +0000 (UTC) (envelope-from m.seaman@infracaninophile.co.uk) Received: from smtp.infracaninophile.co.uk (gate6.infracaninophile.co.uk [IPv6:2001:8b0:151:1::1]) by mx1.freebsd.org (Postfix) with ESMTP id 46DBF8FC19 for ; Sat, 12 Sep 2009 13:10:26 +0000 (UTC) Received: from happy-idiot-talk.infracaninophile.co.uk (localhost [IPv6:::1]) (authenticated bits=0) by smtp.infracaninophile.co.uk (8.14.3/8.14.3) with ESMTP id n8CDAK7Y038478; Sat, 12 Sep 2009 14:10:21 +0100 (BST) (envelope-from m.seaman@infracaninophile.co.uk) X-DKIM: Sendmail DKIM Filter v2.8.3 smtp.infracaninophile.co.uk n8CDAK7Y038478 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infracaninophile.co.uk; s=200708; t=1252761021; bh=sMydcp/sFiCfzSoUe6B5h7/1n8WLnun7eP+7O+cFH6s=; h=Message-ID:Date:From:MIME-Version:To:CC:Subject:References: In-Reply-To:Content-Type:Cc:Content-Type:Date:From:In-Reply-To: Message-ID:Mime-Version:References:To; z=Message-ID:=20<4AAB9DBC.50007@infracaninophile.co.uk>|Date:=20Sat ,=2012=20Sep=202009=2014:10:20=20+0100|From:=20Matthew=20Seaman=20 |Organization:=20Infracaninophile |User-Agent:=20Thunderbird=202.0.0.23=20(X11/20090823)|MIME-Versio n:=201.0|To:=20Maxim=20Khitrov=20|CC:=20Free=2 0BSD=20Questions=20list=20|Subject: =20Re:=20Rule=20equivalence=20of=20pf=20uRPF=20check|References:=2 0<26ddd1750909120549ve82a843k464c1233c3a6f603@mail.gmail.com>|In-R eply-To:=20<26ddd1750909120549ve82a843k464c1233c3a6f603@mail.gmail .com>|X-Enigmail-Version:=200.95.6|Content-Type:=20multipart/signe d=3B=20micalg=3Dpgp-sha256=3B=0D=0A=20protocol=3D"application/pgp- signature"=3B=0D=0A=20boundary=3D"------------enig147C454F3B85CE96 BC8AE59F"; b=4f7ShxmLSLf9RNefbIz2SCSCPIj9G9IfMbZ3L5TScrGe68hHPgNFqEz5e5MX1Oz20 gDQ6H393Q6BnavYLIJbpXPe6svR90TXiGaslYD3T168gf/tEjbK12CGc4UMuudR9ct 1atD6IGWrltuyrk+padaGaZr1fuNgPGjrXNvqsMk= X-Authentication-Warning: happy-idiot-talk.infracaninophile.co.uk: Host localhost [IPv6:::1] claimed to be happy-idiot-talk.infracaninophile.co.uk Message-ID: <4AAB9DBC.50007@infracaninophile.co.uk> Date: Sat, 12 Sep 2009 14:10:20 +0100 From: Matthew Seaman Organization: Infracaninophile User-Agent: Thunderbird 2.0.0.23 (X11/20090823) MIME-Version: 1.0 To: Maxim Khitrov References: <26ddd1750909120549ve82a843k464c1233c3a6f603@mail.gmail.com> In-Reply-To: <26ddd1750909120549ve82a843k464c1233c3a6f603@mail.gmail.com> X-Enigmail-Version: 0.95.6 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="------------enig147C454F3B85CE96BC8AE59F" X-Virus-Scanned: clamav-milter 0.95.2 at happy-idiot-talk.infracaninophile.co.uk X-Virus-Status: Clean X-Spam-Status: No, score=-3.0 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VERIFIED,NO_RELAYS autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on happy-idiot-talk.infracaninophile.co.uk Cc: Free BSD Questions list Subject: Re: Rule equivalence of pf uRPF check X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 12 Sep 2009 13:10:26 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig147C454F3B85CE96BC8AE59F Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Maxim Khitrov wrote: > block in quick on $int_if from !$int_if:network > block in quick on !$int_if from $int_if:network > block in quick from $int_if >=20 > The OpenBSD pf faq states that urpf-check is equivalent to the > antispoof rules, but the antispoof section lists only the last two > rules in my example as being equivalent. So the question is does urpf > imply the first rule as well? Not if uRPF is intended as a general mechanism. What would happen if you applied that on $ext_if (the external interface you connect to the re= st of the internet with)? It's perfectly valid for packets from other than dir= ectly attached networks to be passed by your firewall -- not doing that would, = in fact, completely negate your web browsing experience... Cheers, Matthew --=20 Dr Matthew J Seaman MA, D.Phil. 7 Priory Courtyard Flat 3 PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate Kent, CT11 9PW --------------enig147C454F3B85CE96BC8AE59F Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.13 (FreeBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEAREIAAYFAkqrnbwACgkQ8Mjk52CukIxQWwCfVikOuHY3MR1748HETwZ+PcWK SusAoIEIJ4k/B+u5X6ERasb6TZ2TG0nO =Ybi2 -----END PGP SIGNATURE----- --------------enig147C454F3B85CE96BC8AE59F--